No Tillage Use for Crop Production in Kentucky Counties in 1998

For the past several years, we have reported the status of no~tillage adoption in Kentucky counties. Now, CTICt has published the results for 1998. In 1994, 44% of all crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51 % . In 1997, it dropped to 48% and remains at 48% for 1998. Results for the leading no-till states for 1994, 1996, 1997 and 1998 are shown in Table 1. The percentage of major grain crops (com, soybeans and small grains) grown under no tillage in Kentucky are shown by county in Figure 1. Statewide, the percentage of major grain crops no-tilled in Kentuckv reached 54% in 1996, decreased to 52% in 1997, and remains at 52% in 1998 (Fig. 2)

Effectiveness of Tile Drainage on Karnak Silty Clay Soil

Artificial drainage of agricultural lands has been practiced for centuries. Earlier techniques devised were open ditches to drain the excess water. The widescale development of subsurface tile drains began with the production and availability of clay tiles. Today, corrugated plastic pipe is the most popular and efficient way to install subsurface drainage lines. The objective of agricultural soil drainage is the removal and disposal of excess water from the rooting zone in order to improve soil productivity. The 1971 Soil Conservation Service (SCS) handbook estimated that 130 million acres or about one-third of all crop land in the United States is artificially drained. The reason that some soils do not drain water adequately through the soil profile is usually related to the presence of naturally or artificially compacted layers in the soil profile which are restrictive to water movement. In all such cases the soil has a layer, or layers, of low permeability which does not allow the water to penetrate downward, causing the development of a water table. inadequate drainage can cause many problems for agricultural use. The two most critical problems are an inadequate oxygen supply for normal root growth, causing injury and sometimes death to the crop. The second and third problems are the possibility of late planting and harvesting due to wet land

No Tillage Use for Crop Production in Kentucky Counties in 1996

Two years ago, we reported the status of notillage adoption in Kentucky counties in the year 1994. Now, CTIC has published the results for 1996. As before, Kentucky leads the nation in percent of crops produced under no tillage, but the percentage has increased significantly. In 1994, 44% of crops were produced under no tillage in Kentucky, whereas in 1996, that figure had reached 51 %. The results for both 1994 and 1996 are shown in Table 1. It is evident that Kentucky has both maintained first place and has also increased its lead over the other states. The percentage of crops grown under no tillage in each county is shown in Figure 1. Results by crop and average values for each county and for the state are shown in Table 2

No Tillage Adoption in Grain Crops in Kentucky Counties in 1994

The no-tillage system, where soils are neither tilled nor cultivated, has a number of advantages. Studies in Kentucky and in other states show much lower erosion under no tillage as compared with conventional tillage. In addition, fuel, machinery, and time savings are all impressive when the no-tillage system is used. There is also a tendency toward better crop yields due to higher water capture and/or conservation that is associated with the mulch of crop residues that is maintained on the soil surface in no tillage

Use of Fluorogypsum to Reduce Subsoil Acidity in a Fragipan Soil

In western Kentucky, there are several million acres of fragipan soils which are characterized by both acid subsoils and fragipans which commence at depths of 20 to 30 inches below the soil surface. The combination of subsoil acidity and a fragipan with massive structure impedes root growth and water movement, diminishing, somewhat, the usefulness of the soils for crop production. Alfalfa, a crop which is very sensitive to soil acidity and to poor drainage, was chosen as a test crop to measure the effects of adding fluorogypsum to Sadler silt loam, a soil representative of the fragipan soils found in the western Kentucky coalfields. Fluorogypsum is a by-product produced from the manufacture of hydrofluoric acid from fluorospar and sulfuric acid. It is composed of calcium, sulfate and water. In addition to supplying nutrients, gypsum has been shown to reduce the level of exchangeable acidity in the subsoil

Has the Nitrate-Nitrogen in Streams Draining Agricultural Watersheds in Kentucky Changed in the Last 18 Years?

In 1971 and 1972, we sampled streams across Kentucky for nitrate-nitrogen (NO3-N) during the high-water flow months of January through June. The results were variable and showed a dominant effect of geology and lesser effects of both time and land use on the results. Since that time, use of fertilizer nitrogen (N) has nearly doubled in Kentucky and, further, there is a high degree of concern among the public that NO3-N from fertilizer use may be contaminating streams. The US Environmental Protection Agency has set a maximum of 10 ppm NO3-N in water as being safe for human consumption

The Effect of Organic Matter on Maximum Compactability of Soil

Bulk density is the weight of a given volume of soil expressed by soil scientists as grams per cubic centimeter (g/cm3). The higher the bulk density, the lower the volume of soil occupied by pore space, that volume of soil in which air and water reside. Because of this, there is much interest on the degree to which soil can be compacted. The Proctor test is a means of determining the maximum bulk density that can be attained in a soil sample. This maximum compactibility is widely used on highways and building foundations but has had little use in agricultural soils. In the fall of 1994 we began to determine maximum compactability on samples from plots and fields with variable land use history in Kentucky. This is a report of the preliminary results

An Assessment of Water Sources Related to Major Systems of Agricultural Land Use in Kentucky

Recent years have seen a greater public concern about the quality of the nation\u27s water resources. While initial concerns targeted point source pollution, the emphasis in recent years has shifted to non-point source pollution, including the effect of general practices used by fanners in agricultural production systems. Since there was no reliable data base on such effects for Kentucky, the state\u27s General Assembly passed legislation during its 1990 session directing the University ofKentucky\u27s College of Agriculture (UK.CA) to assess the effect of agricultural practices on quality of the state\u27s waters. As part of the efforts undertaken by the UKCA in this regard, an assessment was made of water sources in major agricultural areas to determine the current level of water quality associated with agricultural practices in those areas. This information was needed to evaluate the question of concern: Do nonpoint agricultural practices such as fertilizer and herbicide use and grazing of pastures by livestock pose a threat to the quality of water potentially serving as human drinking water sources

Solute and Bacterial Transport through Partially-Saturated Intact Soil Blocks

Steady-state transport of water, chloride and bacteria was measured through intact blocks of Maury and Cecil soils, under partially saturated conditions. Major objectives were to determine if transport occurs uniformly or via preferential flow paths, and if soil physical properties could be used to predict breakthrough. The blocks were instrumented with TDR probes and mounted on a vacuum chamber containing 100 cells that collected eflluent. After each experiment the blocks were sampled for soil physical properties. The fluxes showed no spatial autocorrelation and the eflluent variance was not statistically different between soils. Less than 3% of the influent bacteria appeared in the effluent. Maximum bacterial breakthrough occurred after 0.25 water-filled pore volumes had been leached, and was greater for Cecil soil than for Maury soil. The chloride breakthrough curves were fitted to the convection dispersion equation. The best predictor of dispersivity was volumetric water content (R2 = 0.28, P \u3c 0.01), with dispersivity increasing with decreasing water content. Lower water contents lead to more tortuous flow paths and thus, a broadening of the velocity distribution. Soil structural controls on solute dispersion under partially saturated conditions are likely to be indirect, and related to differences in water content at given flux produced by differences in pore-size distribution